First is the already popular Jamie Dimon. On the matter of share buybacks, one letter writer recommends another letter writer:

One CEO who always stresses the price/value factor in repurchase decisions is Jamie Dimonat J.P. Morgan; I recommend that you read his annual letter.

Second was Bank of America's Brian Moynihan, who has been under fire for the way he has managed his bank. Buffett sticks up for him, saying that banks woes weren't his fault:

At Bank of America, some huge mistakes were made by prior management. Brian Moynihan has made excellent progress in cleaning these up, though the completion of that process will take a number of years. Concurrently, he is nurturing a huge and attractive underlying business that will endure long after today’s problems are forgotten.